title: Evidence for Parachlamydia in bovine abortion.
abstract: Bovine abortion of unknown infectious aetiology still remains a major economic problem. In this study, we focused on a new possible abortigenic agent called Parachlamydia acanthamoebae. Retrospective samples (n=235) taken from late-term abortions in cattle were investigated by real-time diagnostic PCR for Chlamydiaceae and Parachlamydia spp., respectively. Histological sections of cases positive by real-time PCR for any Chlamydia-related agent were further examined by immunohistochemistry using specific antibodies. Chlamydophila abortus was detected only in three cases (1.3%) by real-time PCR and ArrayTube Microarray playing a less important role in bovine abortion compared to the situation in small ruminants in Switzerland. By real-time PCR as many as 43 of 235 (18.3%) cases turned out to be positive for Parachlamydia. The presence of Parachlamydia within placental lesions was confirmed in 35 cases (81.4%) by immunohistochemistry. The main histopathological feature in parachlamydial abortion was purulent to necrotizing placentitis (25/43). Parachlamydia should be considered as a new abortigenic agent in Swiss cattle. Since Parachlamydia may be involved in lower respiratory tract infections in humans, bovine abortion material should be handled with care given the possible zoonotic risk.
authors.affiliation: Institute of Veterinary Pathology, University of Zurich, Vetsuisse Faculty, Winterthurerstrasse 268, CH-8057 Zurich, Switzerland.
authors.forename: Silke
authors.initials: S
authors.lastname: Ruhl
authors.forename: Nicola
authors.initials: N
authors.lastname: Casson
authors.forename: Carmen
authors.initials: C
authors.lastname: Kaiser
authors.forename: Ruedi
authors.initials: R
authors.lastname: Thoma
authors.forename: Andreas
authors.initials: A
authors.lastname: Pospischil
authors.forename: Gilbert
authors.initials: G
authors.lastname: Greub
authors.forename: Nicole
authors.initials: N
authors.lastname: Borel
mesh_terms: D000034:Abortion, Veterinary / Q000382:microbiology*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D002695:Chlamydiales / Q000302:isolation & purification*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D010922:Placenta Diseases / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D011247:Pregnancy